—Did you listen to Mr.Jackson’s lecture ?— Yes，I have never heard a _____ one.

 To solve the problem, we would appreciate it if you could give us an ______ explanation and compensate (补偿) us.

Both the summer and the winter Olympic Games are held every four years on a _______ basis.

 _______ his scientific work, he has no time to care for his family affairs, _______, of course, his wife always complains about.

So far we have done a lot to build a low—carbon economy, but it is ____ideal. We have to work still harder.